Converter.



UNTTnn STATES PATENT OFFICE.

XVIIILIAM JOHN KNOX, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR TO GEO.VESTINGHOUSE, OF PITTSBURG, PENNSYLVANIA.

CONVERTER.

SPECIFICATION forming part of Letters Patent No. 710,589, dated October7, 1902.

Application filed November 11,1901. SerialNo. 81,812. (No model.)

To @ZZ 107mm it may concern.:

Beit known that I, WILLIAM JOHN KNOX, a citizen of the United States,and a resident of Edgewood Park, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inLinings for Converters and Furnaces, of which the following is aspecification.

My invention relates to the linings of turnaces, converters, and othervessels used for melting or reducing mattes and other materials orcontaining molten materials.

The invention is particularly applicable to furnaces and converters usedfor treating mattes and refining metals; but it is also applicable tovarious other uses, as will appear.

For convenience of description the inven tion will be more particularlydescribed in connection with furnaces and converters used for treatingcopper inattes.

In certain classes of metallurgical operations it has been customary touse so-called basic linings containing but a small percentage of silica.These have been formed usually by mixing together in a more or lessfinely-divided state magnesite or dolomite and basic slag containingconsiderable silica. These two materials having been mixed are packedagainst the brick lining of the fur-V nace and afterward dried andheated gradually to such a temperature as to cause the silica present tounite with the surfaces of the basic particles by fiuxing therewith, andthus form a binder holding the particles of the lining together more orless firmly. When such a lining is subjected to the actionof the moltenmasses in the operation of the vessel, it is found that the liningitself will disintegrate, and after a relatively small number ofoperations it is necessary to repair or renew the lining. In some casesitis also customary to use a preliminary binding material of tar orother organic material. Such binder is, however, destroyed by theoxidizing action of the flame and is intended merely to hold theparticles in position until they have become more or less solidified bythe drying and heating. The expense of renewing and repairing suchlinings forms a considerable item in the process of treating matte, anda durable lining capable of withstanding the destructive and corrosiveactions of the bath and changes of temperature is an article which haslong been sought for as being of immense value in metallurgicalpurposes. I have found that a lining made by the process described inthis specification fulfils these requirements.

The process whereby I form my lining may be generally described asfollows: A converter or furnace or other vessel of any wellknown usualconstruction having been prepared for receiving the lining is provided,if necessary, with a temporary internal wall, leaving a space to befilled with the refractory lining, and this space is lthen filled with amixture composed principally of a suitable basic material-such, forinstance, as magnesite or chromite (chromium oxid) or any other basicrefractory oxid, and a material which I term oxysulfid of iron and thenature and source of which will be presently described. These materialsare first ground into a comparatively fine condition and thoroughlymixed together in a dry state and a small percentage of what is commonlyknown as water-glass Ythat is to say, a soluble silicate of sodais addedthereto, together with a sufficient amount of water to make the massslightly plastic. The proportion of water-glass added is approximatelysuch an amount as will give the resulting mass from two to three percent. of silica, although this may be variedwithin a considerable range.It should be observed that it is necessary that the oxids used shall beof such a nature or so treated as not to become hydrated or slaked bywater. For example, lime would not be suitable, as the water in thewater-glass or the extra Water that it might be necessary to add to makethe mass sufficiently plastic would cause the lining to slake and swell.The plastic mass thus formed is packed tightly against the outer wall ofthe vessel. For instance, I have obtained good results by packing itbetween a temporary inner lining and the outer wall by means of apneumatic rammer. After the lining has been placed in position theexcess moisture is allowed to evaporate, leaving the material in suchcondition as to be capable of absorbing a solution of calcio chloridwhich is then applied to the inner surface. A convenient process ofapplying this soluff f.

tion consists in spraying it against the surfaces until the mass issaturated therewith. It should be borne in mind that only the excessivemoisture is to be dried out at this point, for if the lining should bethoroughly dried-as, for example, by using the heat of a gas or Wood reor even by long thorough drying in the atmosphere-the Waterglass wouldbecome dried or set and assume the nature of ordinary glass and becomeincapable of uniting With the calcio chlorid. It is therefore desirablethat there be left in the mass a small amount of moisture. This Will notinterfere with the soaking in of the calcic chlorid, as it willpenetrate freely by osmotic action and displacement of any suchmoisture. The action of the calcic chlorid is to combine with the smallamount of silica of the silicate of soda and form calcium silicate andsodium chlorid. It may be noted that the formation of the sodium chloridis incidental to the formation of the calcic silicate. The depth towhich this action takes place depends upon the depth to which the calcicchlorid has been caused to penetrate, and it may be entirely through thelining, if desired, although this is not always necessary. The excess ofmoisture is then thoroughly dried out. The calcio chlorid forms adeposit of minute crystals of calcium silicate upon and between theother particles composing the lining material, thus forming a verytenacious, tough, and durable lining capable of withstanding the actionsto Which it is subjected in the operation of the vessel.

It should be noted that this lining is thoroughly cemented together andis practically in its final condition before being subjected to any veryhigh temperature and little or no change takes place in its conditionunder the influence of high temperatures developed in the subsequentoperations for which the vessel is used. The basic linings formed withbasic slag formed according to the former processes referred to do notbecome cemented together until they have become subjected to such hightemperatures as to cause the silica to be fluxed and unite with thebasic materials.

The oxysuliid of iron, to which reference has'been made, is such amaterial as is formed when an oxid of iron is added to a molten sulfidof iron. In practice I have found it convenient to obtain the oxysuliidof iron in the manner described in another application, filed by meFebruary 4, 1901, Serial No. 45,969, (Patent No. 692,310, dated February4, 1902.)

In practice I have lined a converter for reducin g copper matte in themost careful manner With the magnesite and basic slag composition andalso with a magnesite and tar composition according to the bestpractices and found that the first heat Will materially injure thelining, causing more or less spalling, and at the best have not beenable to use such a lining Without repairing for more than lnasse orcracking Whatever and, in fact,without any apparent injury to thelining.

It should be observed that my improved lining is applied in a verysimple and convenient manner, inasmuch as the materials may be handledin a moist, cold, plastic condition and brought to their nal state withthe use of little or no extraneous heat, although a moderate amount ofheat may, if desired, be used to hasten the drying.

In some cases it may be desired to add calcic chlorid to the basicrefractory oxid and oxysuld of iron mixture before applying the liningto the vessel and subsequently saturate the same with the soluble glass.Usually,how ever. I prefer to add the soluble glass first, for thereason, among others, that the calcio chlorid is highly hygroscopic, andit is thus less easy to dry the lining sufficiently to cause the solubleglass to penetrate.

Vhile I usually prefer to mix about twentyfive per cent. of oxysulfid ofiron with the basic refractory oxid in the formation of the plasticmass, yet it is possible to modify this process by varying the amount ofoxysulld Within Wide limits or even entirely omitting it and proceedingWith the process in other respects in the same manner as described.Under such circumstances the lining will absorb from the bath when it isused in practice considerable amounts of the molten material Which isbeing treated until the lining becomes saturated With such material. Itis also practicable to apply the lining by forming the describedmaterial into blocks or bricks of the proper shape and then build thelining into the vessel.

In the accompanying drawings, Figure 1 is perspective View, partly insection, of a socalled convei-ter, showing the process of applying thelining. Fig. 2 is a cross-section of the same. These figures and thedescription thereof are given merely as illustrative of the generalprocess, proper modifications being made in applying the lining to othervessels.

Referring to the figures, l represents the outer metal shell of thevessel, provided With heads 2 2, secured thereto in any convenientmanner. A tWyer-box 4 is shown here consisting of a series of openings5, the inner ends of Whichterminate within the vessel and the outer endsWithin a space which may be closed by a plate or cover 6. Access to thetwyers is obtained by removing the cover in a manner Well understood. Inpractice I have found that Water-cooled twyers formed of bronze or othersuitable material may be successfully used in connection with myimproved lining. The Water is caused to circulate through spaces 7 insuch manner as to keep the temperature Within the proper limits. Theneck of the converter is represented at S.

IIO

In the drawings, 9 represents a temporary inner lining or support, whichmay be of wood or other suitable material, lea ving a space betweenitself and the outer wall within which the lining material 10,hereinbefore described, is closely packed in the manner alreadydescribed.

It will of course be understood that in such vessels as require anadditional lining-such, for instance, as clay, brick, or other materialbetween the outer shell and the inner liningthe operation is essentiallythe same, such additional lining being placed in position in the usualmanner.

The general process of manufacturing a lining of this character isdescribed in my application, Serial No. 75,440, filed September 16,1901.

I claim as my invention- 1. A vessel for treating copper matte,consisting of an external shell, and a lining composed of a mixture of abasic refractory oXid and oxysulfid of iron and calcium silicate andsodium chlorid.

2. A vessel for treating copper matte, consisting of an external shell,and a lining composed of a mixture of magnesite and oxysuld of iron andcalcium silicate and sodium chlorid, and a water-cooled twyerin contactwith said lining.

3. A vessel for treating copper matte, consisting of an external shelland a lining composed of a mixture of a basic refractory oXid, ametallic compound, and calcio silicate.

Signed at Pittsburg, in the county of Allegheny and State ofPennsylvania, this 7th day of November, A. D. 1901.

WILLIAM JOHN KNOX.

.Vitnesses:

CHARLES FREDERICK MILLER, JOHN ARTHUR ADAMS.

